Psychopharmacology (2003) 168:377–386 DOI 10.1007/s00213-003-1429-7 ORIGINAL INVESTIGATION Susan E. Buffett-Jerrott · Sherry H. Stewart · G. Allen Finley · Heather Lee Loughlan Effects of benzodiazepines on explicit memory in a paediatric surgery setting Received: 22 March 2002 / Accepted: 6 February 2003 / Published online: 4 July 2003  Springer-Verlag 2003 Abstract Rationale: Many laboratory-based studies indi- cate that benzodiazepines impair explicit memory perfor- mance, increase sedation, and impair attention. Objectives: The present study was designed to extend prior lab-based findings to an applied setting in which the amnestic effects of benzodiazepines may be beneficial for users. In addition, the study extended the previous adult- focused research by examining the cognitive effects of benzodiazepines in children. Methods: The present study examined the use of a specific benzodiazepine (midazo- lam) as a premedicant among 40 children aged 4–6 years old having ear tube (myringotomy) surgery, who were randomly assigned to receive midazolam or placebo. Results: Consistent with previous studies, the results indicated that midazolam causes significant amnesia on a cued recall task. In addition, free recall for post-drug events were also impaired by midazolam relative to placebo, indicating that benzodiazepine-induced amnesia occurs even for highly salient information. Conclu- sions: Overall, it appears that benzodiazepines do impair memory in a pediatric population. This amnesia was not secondary to the inattention and sedation also caused by midazolam administration. The theoretical and clinical implications of these findings are discussed, as are potential future studies. Keywords Benzodiazepine · Explicit memory · Midazolam · Surgery Introduction Benzodiazepines are a class of drugs with sedative, anxiolytic, and muscle relaxant effects (Curran 1986). In addition, laboratory research has consistently shown that benzodiazepines produce anterograde amnesia—impaired memory for information learned after drug administration with no impairment for information learned pre-drug (Curran 1986). The present study was designed to extend prior lab-based findings to an applied setting where such amnestic effects might be beneficial (DeJong and Verburg 1988). In addition, it extended previous adult-focused research by examining the cognitive effects of benzodi- azepines in children. Early research indicated that surgical operations can be a particularly stressful experience for children (Eckenhoff 1953). This anxiety contributes to negative postoperative behavioural problems (Kain et al. 1996) and surgical complications (Laycock and McNicol 1988). Both anaes- thesiologists (DeJong and Verburg 1988) and parents (Eckenhoff 1953) have noted that a drug that would decrease anxiety and increase sedation before the induc- tion of anaesthesia might be beneficial. Many anaesthe- siologists (e.g. DeJong and Verburg 1988) have noted that drug-induced amnesia could also be beneficial to children having surgery, as it might attenuate the psychological difficulties associated with separation from parents and/or problematic anaesthesia induction. When the benzodiazepine midazolam was introduced in oral form, researchers suggested that it might be useful as a pre-operative medicant (Smith et al. 1981). Midazo- lam has a short-half life (approximately 2 h) which makes it very useful in a day surgery setting, because patients are not likely to be under the effects of the drug by the time S. E. Buffett-Jerrott ( ) ) Bedford Sackville Community Mental Health (IWK), 70 Memory Lane, Lower Sackville, Nova Scotia, Canada B4C 2J3 e-mail: sjerrott@accesswave.ca Tel.: +1-902-8325704 S. H. Stewart Department of Psychology, Life Sciences Centre, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia, Canada B3H 4J1 G. A. Finley Department of Pediatric Anesthesia, IWK Health Centre, 5850 University Avenue, Halifax, Nova Scotia, Canada B3J 3G9 H. L. Loughlan 83 Vetran’s Avenue, Salisbury, N.B., Canada E4J 2T1